Rectifier cooling system



Oct. 6, 1936 H. WINOGRAD RECTIFIER COOLING SYSTEM Filed Dec. 17, 1932Patented Oct. 6, 1936 UNITED STATES PATENT OFFICE RECTIFIER COOLINGSYSTEM Application December 17, 1932, Serial No. 647,745

5 Claims.

This invention relates to improvements in electron discharge devices andmore particularly to means for maintaining the interior of a device ofthe vapor type at the most favorable conditions. of pressure andtemperature.

- anode thereby causing the occurrence of a socalled backfire. If thevapor pressure is too low, the voltage drop in the arc increasesresulting in a reduced efficiency of the device. The are also becomesunstable and permits the establishment of oscillations or surges in thecircuits connected therewith. The vapor pressure in the arc path isdifficult to regulate as such pressure depends not only on thetemperature of the coldest portion of the device but also on therelative temperatures of the different cooling surfaces and on theamount of vapor evolved in the oathode in dependence on the load of thedevice. The effect of such temperature distribution is such that, evenif portions of the cooling surfaces are well cooled, the flow of largeamounts of vapor from the cathode to such portions and through the arcpath may occur under a relatively high dynamic head so that the pressureof the vapor in the vicinity of the cathode or in the arc path maybecome excessive. Such condition is particularly difiicult to regulatein water-cooled devices for the largest outputs used at the present timein which the amount of vapor generated is so great that the properpressure within the device cannot obtain both at low loads and at heavyoverloads. In devicesknown heretofore the cooling surfaces adjacent thearc path were more intensely cooled than the remainder of the containersurfaces. The result of such cooling was that, upon occurrence of heavyoverloads, large amounts of vapor rising from the cathode rushed towardsthe wall portions adjacent the'arc path whereon such vapor condensed,thereby creating a more or less turbulent zone of high pressure withinthe arc path resulting in the occurrence of frequent backfires.

If the flow of cooling water is so directed as to first cool surfacesnot adjacent to the arc path, any rushes of vapor occurring uponoverloads are diverted outside of the arc path and do not cause theestablishment of dangerous conditions within the device. In addition,the maximum temperature of the coolest portion of the cooling surfacesmay be regulated by thermostatically controlled means.

It is, therefore, among the objects of the present invention to providean electron discharge device of the vapor type in which the pressurewithin the arc path is maintained Within permissible limits at allloads.

Another object of the present invention is to provide an electrondischarge device of the vapor type in which conditions conducive tobackfiring or other disturbances in the operation of the device areavoided.

Another object of the present invention is to provide an electrondischarge device of the vapor type in which the maximum temperature ofthe coolest portion of the cooling surfaces is controlled bythermostatic means.

Another object of the present invention is to provide an electrondischarge device of the vapor type in which the cooling surface portionsadjacent the arc path are automatically maintained at a temperaturehigher than the temperature of other portions of the cooling surface.

Another object of the present invention is to provide an electrondischarge device of the vapor type in which the several cooling membersor surface portions are connected in series to form a single circuit forthe flow of cooling water.

Another object of the present invention is to provide an electrondischarge device of the vapor type in which the cooling surface portionadjacent the arc path is cooled by water previously circulated throughanother cooling portion of the device.

Objects and advantages other than those above set forth will be apparentfrom the following description when read in connection with theaccompanying drawing, which diagrammatically illustrates a cross-sectionof an electron discharge device of the vapor type in which the coolingsurface adjacent the arc path is cooled by water previously circulatedthrough an interior'member of the device.

Referring more particularly to the drawing by characters of reference,the reference numeral l designates the double walled bottom of thedevice which bottom is substantially in the shape of a frustrum of ahollow cone. The aperture through the bottom I is closed by a doublewalled plate 2 insulated from the bottom as at 3. The plate 2 and theinsulation 3 together form a well to retain a quantity of vaporizablematerial such as mercury which forms the cathode 4 of the device. Adouble walled cylinder portion 6 extends upwardly from the bottomportion I and the open upper end of the cylindrical portion is closed bya double walled top plate I having a cylindrical upwardly extendingportion 8 which is also double walled and forms a dome cooperating withthe chamber formed by the bottom I, side walls 6 and top plate I, tocondense the vapor rising from cathode 4.

A plurality of anodes I I are arranged to extend into the chamber fromthe exterior thereof through the top plate 1, the anodes being insulatedfrom the top plate by insulating bushings I2 also extendingtherethrough. Each of the anodes II is partially enclosed by a housingor are guide I3 extending from the insulator I2 to adjacent the bottomI. A coil of tubing I4 is arranged within the chamber, preferably withinthe area enclosed by the anodes I I, and may extend within the domeportion 8 as shown in the drawing. In a device constructed as abovedescribed, the arc will substantially follow a path from anode IIthrough housing I3 along bottom I to cathode 4 as indicated at I5. Itwill be understood that the several members of the device are assembledand sealed in vacuum tight relation by the usual well known means (notshown).

The cooling fluid used for controlling the temperature of the device,which is preferably fresh water obtained from distribution mains (notshown), is admitted through an inlet valve I6 which may be used forregulating the flow of such water but will generally serve only to shutoff the flow of water to permit disconnection of the device from thewater supply mains. The flow of water may first be directed to thechamber enclosed between the walls of cathode plate 2 through tubing Hwhich is generally of insulating material such as rubber hose. The waterhaving circulated within plate 2 flows through another insulating tubesection I8 and is then directed through tubing I9 to cooling coil I4.Tubing 2| directs the water from coil I4 over a thermostatic element 22and through a valve 23 con: trolled by thermostat 22. Valve 23 isbypassed by a manually adjustable valve 24 to permit accurate adjustmentand control of the thermostat 22. The cooling water then flows betweenthe two walls of bottom I and of side walls 6, is con ducted throughtubing 26 to plate 'I, flows between the double walls of such plate andof dome 8 and is discharged through tubing 21 to a drain 28. A gap ismade between tubing 21 and drain 28 in preference to a section ofinsulating tubing so as to permit visual observation of the flow ofwater.

In the arrangement shown, the cooling water is first directed to thecathode for the purpose of preventing the portions of the cathode welland the seals thereof from reaching excessive temperatures and forreducing the amount of vapor generated at the cathode but thetemperature conditions of the device would not be affected materiallyeven if the cathode were cooled by separate cooling means. The coolingwater, at substantially the temperature of the supply mains, thus enterscoil I4 which is thereby maintained at a temperature lower than thetemperature of any of the other cooling surfaces in contact with thevapor. The vapor generated in the cathode will, therefore, tend tocondense on the surface of cooling coil I4 rather than on the otherportions of the cooling surfaces and will rise from cathode 4 in asubstantially rectilinear flow which takes such vapor outside of the arcpath I5. The temperature of the cooling water at the inlet of coil I4,being substantially that of the supply mains, is not controlled but theamount of water circulating through the system is regulated by valve 23so as tomaintain a substantially uniform temperature at thermostat 22.It will thus appear that the temperature of the hottest point of coil I4will be maintained at a substantially constant value by the action ofthermostat 22 and valve 23 irrespective of the amount of heat receivedby coil I4 by condensation of vapor and by radiation from anodes I2,from the arc within the device and from the spot formed by attachment ofthe are on the cathode. Coil I4 will be maintained at the suitabletemperature for condensing the vapor generated at cathode 4 irrespectiveor the amount of such vapor evolved in response to the load carried bythe device. If the flow of water were controlled by valve 23 alone nowater would circulate through the cooling members when the device hasbeen put in operation and has been allowed to reach substantially roomtemperature. The water in coil I4 would gradually reach highertemperatures without, however, affecting thermostat 22 as such hightemperature water would remain within coil I4. To avoid such failure ofthermostat operation, bypass 24 permits the flow of a small amount ofwater even when valve 23 is closed so that the position of thermostat 22is determined by the temperature of the outlet of coil I4 even whenvalve 23 is closed.

It will be seen that bottom I, side wall 6, plate I and dome 3 of thedevice receive water which has been somewhat heated in coil I4 so thatsuch portions of the device are maintained at a temperature higher thanthe temperature of any portion of coil I4. The vapor will, therefore,not tend to condense on such portions which then serve only to dissipateheat radiated by the anodes, by the arc and by the cathode spot. Thevapor generated at the cathode, in excess of the amount to be ionized inthe arc path, therefore flows substantially entirely outside of the arcpath and permits the flow of the arc in a region undisturbed byexcessive pressures caused by the flow of such vapor.

Although but one embodiment of the present invention has beenillustrated and described, it will be apparent to those skilled in theart that various changes and modifications may be made therein withoutdeparting from the spirit of the invention or from the scope of theappended claims.

It is claimed and desired to secure by Letters Patent:

1. In combination with an electron discharge device of the arcing typecomprising a casing having an aperture therein and being provided withdouble walled portions forming a passage for the flow of cooling mediumtherethrough, a receptacle containing a quantity of vaporizable cathodematerial closing said aperture and having a double walled portionforming a passage for the flow of cooling medium therethrough, aplurality of anodes depending into said casing, and an element supportedwithin said casing within the area defined by said anodes having apassage therethrough for the flow of cooling medium, of meansinterconnecting said passages in such manner as to form a continuouspath for the flow of a cooling medium supplied thereto successivelythrough the second, third and first said passages whereby the coolestsurfaces for condensation of vaporized portions of said cathode materialare disposed outside the path of arcs between the said anodes andcathode, and means operable responsive to and in dependence upon thetemperature of said medium flowing from the third said passage into thefirst said passage for regulating the rate of flow thereof therethrough.

2. In combination with an electron discharge device of the arcing typecomprising a casing having an aperture therein and being provided withdouble walled portions forming a passage for flow of cooling mediumtherethrough, a receptacle containing a quantity of vaporizable cathodematerial closing said aperture and having a double walled portionforming a passage for flow of cooling medium therethrough, a pluralityof anodes depending into said casing, and means comprising a coil oftubing supported within said casing within the area defined by saidanodes constituting a passage for flow of cooling medium therethrough,of means interconnecting said passages in such manner as to formtherewith a continuous path for the flow of cooling medium suppliedthereto successively through the second, third and first said passageswhereby vapor created from said cathode material is drawn away from thepaths of arcs between said anodes and cathode, a valve included in theconnections of said medium with said passages for regulating the rate offlow thereof, and means operable responsive to and in dependence uponthe temperature of said medium flowing from the third said passage intothe first said passage for variably operating said valve.

3. In combination with an electron discharge device of the arcing typecomprising a casing having an aperture therein and being provided withdouble walled portions forming a passage for the flow of cooling mediumtherethrough, a receptacle containing a quantity of vaporizable cathodematerial closing said aperture and having a double walled. portionforming a passage for flow of cooling medium therethrough, a pluralityof anodes depending into said casing, and means comprising a coil oftubing supported within said casing within the area defined by saidanodes constituting a passage for the flow of cooling mediumtherethrough, of means interconnecting said passages in such manner asto form a continuous path for flow of a cooling medium supplied theretosuccessively through the second, third and first said passages wherebyvapor created from said cathode material is drawn away from andcondensed outside of the paths of arcs between said anodes and cathode,a valve included in the connections of said medium with said passagesfor regulating the rate of flow thereof, thermostatic means operableresponsive to and in dependence upon the temperature of said mediumflowing through said passages for variably operating said valve, and aby-pass about said valve forming a path for flow of said medium throughsaid passages during periods of closure of said valve.

l. In combination with an electric current rectifier having a closedcasing and containing vaporizecl electrode material, of means forming apath for the flow therethrough of a cooling medium continuously suppliedthereto and arranged in such position within said casing as to afiectthe direction of fiow of said vaporized material, and means operableresponsive to and in dependence upon the temperature of said mediumflowing from the first said means for regulating the rate of flow ofsaid medium therethrough.

5. In combination with an electric current rectifier having a closedcasing and containing vaporized' electrode material, of means comprisinga coil forming a path for the flow therethrough of a cooling mediumcontinuously supplied thereto and arranged in such position within saidcasing as to affect the direction of flow of said vaporized material,and means operable responsive to and in dependence upon the temperatureof said medium flowing from said coil for regulating the rate of flow ofsaid medium therethrough.

HAROLD WINOGRAD.

